Secretion of cytokines and heat shock protein (HspA1A) by ovarian cancer cells depending on the tumor type and stage of disease

Epithelial ovarian cancer is a heterogeneous disease comprising several tumor types that each have multiple histopathological features and different biological behaviors. Recent morphologic and molecular genetic studies have allowed for the categorization of various types of ovarian cancer into two groups: type I and type II. Type I tumors are low-grade and are genetically more stable, while type II tumors are high-grade and genetically unstable. The determination of the type of ovarian cancer may have implications in terms of the appropriate therapeutic strategy because different prognoses and responses to chemotherapeutic agents are observed. Therefore, the current challenge is better recognition of the features of cancer cells, which may result in more individualized therapy. The aim of the current studies was to compare the ability of ovarian cancer cells isolated from tumors, which were classified as type I or type II ovarian cancer, to release pro-inflammatory and immunosuppressive cytokines and heat shock protein (HspA1A). These factors are known to facilitate tumor cell survival, invasion and metastasis. Our studies demonstrated that ovarian cancer cells isolated from patients with type II tumors released high levels of immunosuppressive cytokines (i.e., interleukin 10 and transforming growth factor β) and HspA1A in vitro. Conversely, ovarian cancer cells obtained from of type I tumors were significantly less active. We did not observe any difference in the ability of the isolated cancer cells to secrete pro-inflammatory cytokines, regardless of the type of ovarian cancer. In this study, we found that cancer cells from patients with type II tumors demonstrated more intense activity in regards to survival and metastasis, which should be considered during therapy.

Mycobacterium tuberculosis RecA is indispensable for inhibition of the mitogen-activated protein kinase-dependent bactericidal activity of THP-1-derived macrophages in vitro

Our knowledge about the mechanisms utilized by Mycobacterium tuberculosis to survive inside macrophages is still incomplete. One of the mechanism that protects M. tuberculosis from the host's microbicidal products and allows bacteria to survive involves DNA repair systems such as the homologous recombination (HR) and nonhomologous end-joining (NHEJ) pathways. It is accepted that any pathway that contributes to genome maintenance should be considered as potentially important virulence factor. In these studies, we investigated reactive oxygen species, nitric oxide and tumor necrosis factor-α production by macrophages infected with wild-type M. tuberculosis, with an HR-defective mutant (∆recA), with an NHEJ-defective mutant [∆(ku,ligD)], with a mutant defective for both HR and NHEJ [∆(ku,ligD,recA)], or with appropriate complemented strains. We also assessed the involvement of extracellular signal-regulated kinases (ERKs) 1 and 2 in the response of macrophages to infection with the above-mentioned strains, and ERK1/2 phosphorylation in M. tuberculosis-infected macrophages. We found that mutants lacking RecA induced a greater bactericidal response by macrophages than did the wild-type strain or an NHEJ-defective mutant, and activated ERK1/2 was involved only in the response of macrophages to recA deletion mutants [∆(ku,ligD,recA) and ∆recA]. We also demonstrated that only the triple mutant induced ERK1/2 phosphorylation in phorbol-12-myristate-13-acetate-stimulated macrophages. Moreover, HR-defective mutants induced lower amounts of tumor necrosis factor-α secretion than did the wild-type or ∆(ku,ligD). Our results indicate that RecA contributes to M. tuberculosis virulence, and also suggest that diminished ERK1/2 activation in macrophages infected with M. tuberculosis possessing recA may be an important mechanism by which wild-type mycobacteria escape intracellular killing.

Cholesterol oxidase binds TLR2 and modulates functional responses of human macrophages

Cholesterol oxidase (ChoD) is considered to be an important virulence factor for Mycobacterium tuberculosis (Mtb), but its influence on macrophage activity is unknown. Here we used Nocardia erythropolis ChoD, which is very similar to the Mtb enzyme (70% identity at the amino-acid level), to evaluate the impact of bacterial ChoD on the activity of THP-1-derived macrophages in vitro. We found that ChoD decreased the surface expression of Toll-like receptor type 2 (TLR2) and complement receptor 3 (CR3) on these macrophages. Flow cytometry and confocal microscopy showed that ChoD competed with lipoteichoic acid for ligand binding sites on TLR2 but not on CR3, suggesting that ChoD signaling is mediated via TLR2. Binding of ChoD to the membrane of macrophages had diverse effects on the activity of macrophages, activating p38 mitogen activated kinase and stimulating production of a large amount of interleukin-10. Moreover, ChoD primed macrophages to enhance the production of reactive oxygen species in response to the phorbol myristate acetate, which was reduced by "switching off" TLR-derived signaling through interleukin-1 receptor-associated kinases 1 and 4 inhibition. Our study revealed that ChoD interacts directly with macrophages via TLR2 and influences the biological activity of macrophages during the development of the initial response to infection.

Either non-homologous ends joining or homologous recombination is required to repair double-strand breaks in the genome of macrophage-internalized Mycobacterium tuberculosis

The intracellular pathogen Mycobacterium tuberculosis (Mtb) is constantly exposed to a multitude of hostile conditions and is confronted by a variety of potentially DNA-damaging assaults in vivo, primarily from host-generated antimicrobial toxic radicals. Exposure to reactive nitrogen species and/or reactive oxygen species causes different types of DNA damage, including oxidation, depurination, methylation and deamination, that can result in single- or double-strand breaks (DSBs). These breaks affect the integrity of the whole genome and, when left unrepaired, can lead to cell death. Here, we investigated the role of the DSB repair pathways, homologous recombination (HR) and non-homologous ends joining (NHEJ), in the survival of Mtb inside macrophages. To this end, we constructed Mtb strains defective for HR (ΔrecA), NHEJ [Δ(ku,ligD)], or both DSB repair systems [Δ(ku,ligD,recA)]. Experiments using these strains revealed that either HR or NHEJ is sufficient for the survival and propagation of tubercle bacilli inside macrophages. Inhibition of nitric oxide or superoxide anion production with L-NIL or apocynin, respectively, enabled the Δ(ku,ligD,recA) mutant strain lacking both systems to survive intracellularly. Complementation of the Δ(ku,ligD,recA) mutant with an intact recA or ku-ligD rescued the ability of Mtb to propagate inside macrophages.

Nitric oxide donors: spermine/NO and diethylenetriamine/NO induce ovarian cancer cell death and affect STAT3 and AKT signaling proteins

The important features of cancer cells are uncontrolled growth and proliferation, as well as the ability to metastasis. These features depend mainly on the constant overexpression and activity of various cell signaling proteins, such as signal transducer and activator of transcription 3 (STAT3) and serine-threonine protein kinase AKT proteins. Nitric oxide (NO) has the potential of being anti-tumoral agent, however the exact character of anti-tumoral action of NO is still a matter of debate. In our research we used two NO donors, belonging to NONOates family, with different half-life times: spermine nitric oxide complex hydrate (SPER/NO t1/2=39min) and diethylenetriamine nitric oxide adduct (DETA/NO, t1/2=20h). We evaluated the cytotoxic effect of aforementioned NO donors on SK-OV-3 and OVCAR-3 ovarian cancer cell lines, as well as their effect on posttranslational modification of STAT3 and AKT proteins in these cells. We found that both NO donors present cytotoxic activity on the cancer cell lines, mainly through the induction of apoptosis. What is more, at the high concentration and longer exposure time they were also capable of inducing late apoptosis/necrosis. Both NO donors inhibited STAT3 and AKT3 proteins phosphorylation and down regulated their cytosolic levels, with DETA/NO being stronger inhibitor. We suggests, that NO donors have the potential to act as anti-tumoral agent through inhibiting cancer cell signaling and reducing their viability.

Cholesterol oxidase is indispensable in the pathogenesis of Mycobacterium tuberculosis

Despite considerable research effort, the molecular mechanisms of Mycobacterium tuberculosis (Mtb) virulence remain unclear. Cholesterol oxidase (ChoD), an extracellular enzyme capable of converting cholesterol to its 3-keto-4-ene derivative, cholestenone, has been proposed to play a role in the virulence of Mtb. Here, we verified the hypothesis that ChoD is capable of modifying the bactericidal and pro-inflammatory activity of human macrophages. We also sought to determine the contribution of complement receptor 3 (CR3)- and Toll-like receptor 2 (TLR2)-mediated signaling pathways in the development of macrophage responses to Mtb. We found that intracellular replication of an Mtb mutant lacking a functional choD gene (ΔchoD) was less efficient in macrophages than that of the wild-type strain. Blocking CR3 and TLR2 with monoclonal antibodies enhanced survival of ΔchoD inside macrophages. We also showed that, in contrast to wild-type Mtb, the ΔchoD strain induced nitric oxide production in macrophages, an action that depended on the TLR2, but not the CR3, signaling pathway. Both wild-type and mutant strains inhibited the production of reactive oxygen species (ROS), but the ΔchoD strain did so to a significantly lesser extent. Blocking TLR2-mediated signaling abolished the inhibitory effect of wild-type Mtb on ROS production by macrophages. Wild-type Mtb, but not the ΔchoD strain, decreased phorbol myristate acetate-induced phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), which are involved in both TLR2- and CR3-mediated signaling pathways. Our finding also revealed that the production of interleukin 10 by macrophages was significantly lower in ΔchoD-infected macrophages than in wild-type Mtb-infected macrophages. However, tumor necrosis factor-α production by macrophages was the same after infection with mutant or wild-type strains. In summary, we demonstrate here that ChoD is required for Mtb interference with the TLR2-mediated signaling pathway and subsequent intracellular growth and survival of the pathogen in human macrophages.

The role of 3-ketosteroid 1(2)-dehydrogenase in the pathogenicity of Mycobacterium tuberculosis

Background

A growing body of evidence suggests that Mycobacterium tuberculosis (Mtb) uses the host’s cholesterol as a source of carbon and energy during infection. Strains defective in cholesterol transport or degradation exhibit attenuated growth in activated macrophages and diminished infectivity in animal models. The aim of this study was to evaluate intracellular replication of a cholesterol degradation-deficient Mtb mutant in human macrophages (MØ) in vitro and assess the functional responses of Mtb mutant-infected MØ.

Results

A mutant Mtb H37Rv strain containing an inactivated kstD gene (∆kstD), which encodes 3-ketosteroid 1(2)-dehydrogenase (KstD), was previously prepared using the homologous recombination-based gene-replacement technique. A control strain carrying the kstD gene complemented with an intact kstD was also previously constructed. In this study, human resting MØ were obtained after overnight differentiation of the human monocyte-macrophage cell line THP-1. Resting MØ were further activated with interferon-γ (IFN-γ). The ability of the kstD-defective Mtb mutant strain to replicate intracellularly in human MØ was evaluated using a colony-forming assay. Nitric oxide (NO) and reactive oxygen species (ROS) production by MØ infected with wild-type or ∆kstD strains was detected using Griess reagent and chemiluminescence methods, respectively. The production of tumor necrosis factor-α and interleukin-10 by MØ after infection with wild-type or mutant Mtb was examined using enzyme-linked immunosorbent assays.

We found that replication of mutant Mtb was attenuated in resting MØ compared to the wild-type or complemented strains. Moreover, the mutant was unable to inhibit the NO and ROS production induced through Toll-like receptor 2 (TLR2) signaling in infected resting MØ. In contrast, mutant and wild-type Mtb behaved similarly in MØ activated with IFN-γ before and during infection.

Conclusions

The Mtb mutant ∆kstD strain, which is unable to use cholesterol as a source of carbon and energy, has a limited ability to multiply in resting MØ following infection, reflecting a failure of the ∆kstD strain to inhibit the TLR2-dependent bactericidal activity of resting MØ.

The interaction of HspA1A with TLR2 and TLR4 in the response of neutrophils induced by ovarian cancer cells in vitro

Inducible heat shock protein (HspA1A) promotes tumor cell growth and survival. It also interacts with effector cells of the innate immune system and affects their activity. Recently, we showed that the direct contact of ovarian cancer cells, isolated from tumor specimens, with neutrophils intensified their biological functions. Our current experiments demonstrate that the activation of neutrophils, followed by an increased production of reactive oxygen species, by cancer cells involves the interaction of HspA1A from cancer cells with Toll-like receptors 2 and 4 expressed on the neutrophils' surface. Our data may have a practical implication for targeted anticancer therapies based, among other factors, on the inhibition of HspA1A expression in the cancer cells.

JAK3, STAT3 and CD3-zeta signaling proteins status in regard to the lymphocytes function in patients with ovarian cancer

Several groups of author have published that, in most cases of carcinoma, circulating lymphocytes are unable to carry out immune functions successfully. A molecular mechanism responsible for T lymphocytes defective reactivity in cancer patients is not completely defined. We evaluated whether the impaired function of peripheral blood lymphocytes (PBLs) from ovarian cancer patients could be associated with signaling elements such as JAK3, STAT3 and CD3-zeta chain. The study addressed to the simultaneous expression and phosphorylation status of mentioned molecules evaluation in regard to lymphocyte function in patients with advanced ovarian cancer has not yet been demonstrated by others. We found that PBLs of cancer patients showed lower JAK3, CD3-zeta molecules expression levels, as well as lower STAT3 and CD3-zeta phosphorylation levels than cells of control. The lower proliferative response and IL-2 production capacity of cancer patients PBLs in comparison with that of the control group cells were the functional consequences of reported in this study signaling abnormalities.

Signal transduction pathways affected by nitric oxide donors during neutrophil functional response in vitro

OBJECTIVE AND DESIGN

We investigated the intracellular signalling pathways by which nitric oxide (NO) donors: diethylamine/NO (DEA/NO) and 3-morpholinosydnonimine (SIN-1) regulate the functional response of human neutrophils to activating stimuli.

METHODS

The phosphorylation and nitration of signalling proteins, cyclic GMP level, neutrophil respiratory burst and adhesive activities and CD11b/CD18 molecule expression on neutrophils in the presence and absence of soluble guanylate cyclase inhibitors were determined.

RESULTS

NO donors showed strong inhibitory effect on activated neutrophils. NO donors nitrated the tyrosine residues in signalling proteins causing a decrease in tyrosine phosphorylation and neutrophils response to activation. Diethylamine/NO employed cyclic GMP as a signalling molecule in its action on neutrophils, whereas peroxynitrite anion donor affected neutrophil functions in a cGMP-independent manner. Moreover, we observed that peroxynitrite anion can overcome the nitric oxide molecule action.

CONCLUSIONS

We conclude that each NO donor depending on its concentration and chemical nature may act on different elements of neutrophil signalling pathways capable of inducing distinct neutrophil functions.

Application of intracellular alkaline phosphatase activity measurement in detection of neutrophil adherence in vitro

We have proposed the use of the fluorimetric method with 4-methylumbelliferyl phosphate (4-MUP) specific substrate for the alkaline phosphatase determination in the neutrophil adhesion assay. We provide evidence that the endogenous neutrophil alkaline phosphatase (NAP) activity evaluation is reliable to quantify neutrophil adhesion at a wide range of cell numbers (10(4)-10(6)). The results obtained by fluorimetric NAP activity test correlate to the results of adherence evaluated using the MTT reduction assay. The fluorimetric NAP activity test may be applied for resting as well as activated neutrophils without the risk of the activators interferences into the test. The alkaline phosphatase survey with the use of 4-MUP substrate is recommended herein as a sensitive, repeatable, simple, and reliable method of the neutrophil adherence determination in vitro.

Flow cytometric evaluation of human neutrophil apoptosis during nitric oxide generation in vitro: the role of exogenous antioxidants

Among numerous inflammatory mediators a nitric oxide molecule is supposed to be important in the modulation of neutrophil survival in vivo and in vitro. The effect of exogenous supply of NO donors such as SNP, SIN-1, and GEA-3162 on the course of human neutrophil apoptosis and the role of extracellular antioxidants in this process was investigated. Isolated from peripheral blood, neutrophils were cultured in the presence or absence of NO donor compounds and antioxidants for 8, 12, and 20 hours. Apoptosis of neutrophils was determined in vitro by flow cytometric analysis of cellular DNA content and Annexin V protein binding to the cell surface. Exposure of human neutrophils to GEA-3162 and SIN-1 significantly accelerates and enhances their apoptosis in vitro in a time-dependent fashion. In the presence of SNP, intensification of apoptosis has not been revealed until 12 hours after the culture. The inhibition of GEA-3162- and SIN-1-mediated neutrophil apoptosis by superoxide dismutase (SOD) but not by catalase (CAT) was observed. Our results show that SOD and CAT can protect neutrophils against NO-donors-induced apoptosis and suggest that the interaction of NO and oxygen metabolites signals may determine the destructive or protective role of NO donor compounds during apoptotic neutrophil death.

Oxidative and adhesive responses of human neutrophils to nitrovasodilators in vitro: the role of protein kinases

BACKGROUND

Sodium nitroprusside (SNP) and molsidomine are used in the treatment of coronary heart disease. Since the neutrophils play a pathological role in ischaemic heart disease, it is important to understand the direct action of nitrovasodilators on their function.

AIM

We examined the effects of SNP and 3-morpholinosydnonimine (SIN-1, molsidomine metabolite) on the respiratory burst of human neutrophils and their adhesion in vitro . The influence of nitric oxide (NO)donors on the activity of protein kinases, which are involved in the NADPH oxidase activation, was also investigated.

METHODS

The respiratory burst of neutrophils was determined by chemiluminescence and fluorescence methods, while the adhesion was assayed by adherence of neutrophils to the plastic surface.

RESULTS

NO donors decreased the oxidative burst of activated neutrophils. However, the effects of SNP and SIN-1 strongly depended on the treatment time of neutrophils and on the stimulus employed to cells activation. Protein kinase C inhibitor did not prevent the inhibitory effect of SIN-1, but diminished the inhibitory effect of SNP on the neutrophils' respiratory burst. Protein tyrosine kinase inhibitor did not affect the action of SNP, but diminished the inhibitory effect of SIN-1 on fMLP-stimulated but not on PMA stimulated oxidative burst of neutrophils. This suggests that SNP action is mainly associated with protein kinase C, while SIN-1 is associated with protein tyrosine kinase activity. We also found that SIN-1 but not SNP diminished the adhesive activity of neutrophils.

CONCLUSIONS

Our data show that SIN-1 biological effect on some neutrophils activity is different from both spermine NONOate and SNP, and mainly depends on ONOO(-), while SNP action is mediated by NO.

Effects of uraemia and haemodialysis on neutrophil apoptosis and expression of apoptosis-related proteins

BACKGROUND

In haemodialysis (HD) patients, it is unclear whether increased apoptosis of neutrophils is due to uraemia or HD itself. The purpose of the current study was to assess the effect of uraemia and HD on the rate of apoptosis and apoptosis-related protein expression in whole blood neutrophils.

METHODS

We employed a whole-blood micromethod to test spontaneous apoptosis and expression of apoptosis-regulating proteins in cultured neutrophils from uraemic patients (pre-HD), HD patients and healthy controls. Blood samples were drawn before, after 20 min and after 4 h of haemodialysis, and were then cultured for 20 h. We evaluated the rate of apoptosis from annexin V and propidium iodide staining, and examined bcl-2, Fas/Apo-1 and p53 expression in the cultured neutrophils.

RESULTS

Fas/APO-1 expression and total percentage of apoptotic whole blood neutrophils of pre-HD and HD patients before HD were significantly higher than controls. There was a transient but significant decrease in the percentage of apoptotic neutrophils and Fas/APO-1 expression after 20 min of dialysis. The expression of bcl-2 protein was significantly lower from neutrophils in HD patients compared with controls, and HD significantly downregulated bcl-2 expression. The p53 protein content in HD patients before HD was significantly higher than in pre-HD patients.

CONCLUSIONS

These findings suggest that uraemia accelerates neutrophil apoptosis by increasing Fas/Apo-1, and that HD does not affect neutrophil apoptosis more than uraemia. In addition, HD produces only in a transient sequestration of potentially apoptotic neutrophils.

The effect of interleukin-6 on hepatitis B virus replication in peripheral blood mononuclear cells in vitro

Although the major target organ for hepatitis B virus (HBV) is the liver, the possibility of infection of peripheral blood mononuclear cells (PBMCs) with HBV has also been reported. This study was performed to analyze the course of HBV infection of PBMCs and to investigate the influence of interleukin-6 (IL-6) on the efficiency of infection of PBMCs with HBV in vitro. PBMCs isolated from a healthy donor were infected by exposing to a HBsAg-, HBeAg-positive serum in the presence or absence of exogenous IL-6. The efficiency of infection was estimated by HBV DNA determination in the cells and medium in the course of infection. The results of this study show that the presence of IL-6 during the PBMCs infection with HBV increased the efficiency of this infection.

Involvement of nitric oxide donor compounds in the bactericidal activity of human neutrophils in vitro

The bactericidal activity of human neutrophils against extracellular and facultatively intracellular bacteria was studied in the presence of the nitric oxide (NO) donors sodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1), a molsidomine metabolite. SNP and molsidomine are drugs commonly used as nitrovasodilators in coronary heart disease. It is demonstrated here that the NO donor compounds themselves did not affect the viability and survival of the bacterial strains tested. Neither SNP nor SIN-1 had any effect on the process of bacteria ingestion. In contrast, NO donors enhanced the ability of neutrophils to kill Escherichia coli, Proteus vulgaris and Salmonella Anatum. However, strains differed in their susceptibility to SNP- and SIN-1-mediated killing by neutrophils. Removal of the superoxide anion reduced the bactericidal activity of SNP- and SIN-1-treated neutrophils against E. coli and S. Anatum. This suggests that the NO derivatives formed in the reaction of NO generated from donors with the reactive oxygen species released by phagocytosed neutrophils potentiate the bactericidal activity of human neutrophils in vitro. The above original observation discussed here suggests clinical significance for the treatment of patients with nitrovasodilators in the course of coronary heart disease therapy.

Influence of opioid peptides on human neutrophil apoptosis and activation in vitro

BACKGROUND

It has been shown that cells of the immune system release opioid peptides and possess receptors for them. The concentrations of opioid peptides in the peripheral circulation rapidly increase during inflammation and acute stress response.

AIMS

The effect of opioid peptides Met-enkephalin (M-ENK) and beta-endorphin (beta-END) on the oxidative metabolism of normal human neutrophils and their death by apoptosis in vitro was investigated.

METHODS

Isolated from peripheral blood, neutrophils were incubated in the presence or absence of 10(-6) to 10(-10) M of M-ENK and beta-END for 12 and 18 h. Apoptosis of neutrophils was determined in vitro by flow cytometric analysis of cellular DNA content and Annexin V-FITC protein binding to the cell surface. The MTT-reduction assay was employed to estimate the oxidative metabolism of neutrophils.

RESULTS

Treatment with M-ENK caused a significant increase in apoptotic cells after 18 h of culture: *0 M (control) versus 10(-10) M, p < or = 0.02; **10(-10) M versus 10(-10) M, p < or = 0.02. Treatment with beta-END caused a significant increase in apoptotic cells after 12 h of culture: 0 M versus 10(-8) M, p < or = 0.03; **0 M versus 10(-10) M, p < or = 0.04. We found the significant increase in MTT reduction by neutrophils in the presence of M-ENK and beta-END both before and after the culture. However, the ability of neutrophils to reduce the MTT salt to formazan decreased significantly after the culture.

CONCLUSIONS

We observed that the in vitro effect of opioid peptides on the neutrophil survival and their functional state was time and dose dependent. The presence of antioxidants in the culture medium modifies neutrophil survival.

Spontaneous apoptosis of neutrophils in whole blood and its relation to apoptosis gene proteins

Apoptosis of neutrophils limits their pro-inflammatory potential. We tested the ability of fresh and cultured whole blood neutrophils to undergo spontaneous apoptosis and expression of p53, Fas/Apo-1, bcl-2 protein in the cells using flow cytometry. Neutrophil apoptosis was estimated using Annexin V and propidium iodide binding and verified under light microscopy. The percentage of early and late apoptotic neutrophils in the blood samples increased significantly after 20 h culture from 12.3 +/- 14.2% and 4.3 +/- 4.2% to 39.5 +/- 14% and 15.3 +/- 9.6%, respectively. The majority of late apoptotic neutrophils had altered morphology in FSC/SSC dot plot compared to alive or early apoptotic neutrophils. Cultured neutrophils presented markedly lower expression of bcl-2 protein compared to fresh blood cells: 211 +/- 321 median of fluorescence intensity (MFI) and 787 +/- 1152 MFI, respectively. The increased percentage of late apoptotic cells after culture paralleled the increase in the Fas/Apo-1 expression and negatively correlated with bcl-2 expression. We noted intracellular expression of p53 protein in neutrophils, although the expression did not correlate neither to the percentage of the apoptotic neutrophils, nor to the Fas/Apo-1 or bcl-2 expression. Our results suggested that neutrophil apoptosis is gene regulated, moreover, we present a possibility to assess the neutrophil apoptosis and cellular expression of the proteins of apoptosis related genes in whole blood samples.

Immunological status of competitive cyclists before and after the training season

The total number of leucocytes, T lymphocyte subsets, mitogen induced proliferation of lymphocytes, Il-2 generation, adherence capacity and chemiluminescence of granulocytes were measured and a leukergy test performed in fifteen young cyclists. The investigations were carried out at rest at the beginning of a training season and after six months of intensive training and a racing season, cycling approximately 500 km a week. Baseline values of the tested immune parameters were within the range observed in 16 non-trained healthy controls except significantly increased non stimulated neutrophil chemiluminescence. The second cyclo-ergometer test in August showed a marked improvement in the performance capacity of the cyclists. Significant decrease in absolute numbers of CD3+ and CD4+ cells, diminished IL-2 generation and fMLP and PMA stimulated chemiluminescence of neutrophils were noted. Surprisingly, a marked increase in lymphocyte proliferation induced by PHA and anti-CD3 MoAb and normalisation in non stimulated neutrophil chemiluminescence were also observed at rest after the training season. We conclude that long-lasting intensive training may result in significant alterations in lymphocyte number and composition and in neutrophil oxidative burst capacity, but their actual significance for immunity is seen controversially.

Involvement of granulocyte factor (GF) in receptor-triggered stimulation of lymphocytes and neutrophils

Granulocyte factor derived from the specific granules of polymorphonuclear neutrophils affects mitogen--and alloantigen--induced proliferation of human lymphocytes "in vitro". A dual pattern of GF effect was noted: inhibition of mitogen induced lymphocyte proliferation in higher concentrations and costimulatory activity in lower concentrations of GF. GF induced the lymphocyte proliferation in combination with phorbol ester (PMA) or anti-CD2 monoclonal antibodies (mAb) with PMA. Other combinations of anti-CD2 and anti-CD3 mAb with GF do not augment the proliferation. The comitogenic activities of GF are associated with IL-2 production and IL-2R expression. Specific binding of labelled GF to stimulated lymphocytes suggests that it may recognize the specific molecule expressed only an activated cells. GF diminishes the zymosan-induced granulocyte stimulation, but GF acts as a stimulator of granulocyte O2 production. GF may recognize common targets on leukocytes. Leukocyte adhesive glycoproteins may be such putative targets.

Effect of endotracheal anaesthesia on the activity of lysosomal enzymes in peripheral blood granulocytes

The purpose of this study was to assess the effect of endotracheal anaesthesia on the activity of lysosomal enzymes in peripheral blood granulocytes. The determinations were carried out before anaesthesia, after 1 hour of anaesthesia and 1 hour after awakening. The activity of lysosomal enzymes was assessed on the basis of the activity of marker-enzymes, i.e. acid phosphatase, acid protease and neutral protease. The lysosomal fraction was prepared by Choduker's method and the activity of lysosomal enzymes was calculated for 100 mug of protein. The obtained results showed a statistically not significant rise in the activity of these enzymes in the lysosomes during anaesthesia without a similar rise in the supernatant. The activity of marker enzymes in lysosomes rose to the initial values after the awakening of patients. Such rapid changes in the activity of lysosomal enzymes seem to depend mainly on the mobilization of the reserve pool of granulocytes from other sources than the peripheral blood and, to a lesser extent, on latency and stabilization of lysosomal membranes by anaesthetic agents used in correctly conducted anaesthesia.